Don,
my boat is the newer style and came with an Origo two burner canister style stove. It has two pot clamps that mount on a rail that runs along the front of the stove. they are held in place with a thumb screw.
I've done the Port/Huron to Mac three time - but never on my J/30. Did it once on a Hobie 33 - talk about an uncomfortable and wet ride. No hot meals, no hot coffee. Skipper even wanted us to drink lake water and not bring beer.
Here's my reccomendation. It gets cold at night on that race, if possibe try to serve at least one hot meal a day and have the ability to serve hot coffee.
The ice box is plenty big, I suggest two blocks and one bag of ice. for the blocks, fill gallon jugs with water and freeze it before. that way you'll have ice and water. That should get you through 3 days and 2 nights. Take another big cooler for beer, again use frozen gallon jugs of water for ice. If you put blocks or cubes in the cooler when the ice melts the water can spill out when the boat is heeled or pounding through waves.
I work in Novi and have customers over in Oxford. Maybe we can get together for lunch or a beer some time.